Comfort

Air temperature Surrounding surfaces temperature Thermal criteria : Thermal permeability Relative air speed Relative air humidity Air quality : Air purity, odors Noise level, noise pollution Acoustic : Reverberation time (echo duration) Natural and artificial lighting Colors Visual : Interior volumes distribution Level of occupancy Other influences : "ambiance"

Comfort: Sensitivity to factors

0 1 2 3

Température de l'air

mpérature des surfaces

Courants d'air

Rayonnement solaire

Humidité de l'air

Pureté de l'air

Eclairage

Couleur

BruitsNoise

Color

Lighting

Air purity

Air humidity

Solar radiation

Drafts

Surfaces temperature

Air temperature

Visual comfort

Key aspects of daylit environmentVisual performancePhysiological conditionsVisual quality

Visual comfort

Key aspects of daylit environment

ObjectivesHarmonious luminance distribution (no strong contrasts)Good color rendering (continuous spectrum, appropriate color T°) Adequate illuminance levelNo disturbing reflectionsNo direct glare

Visual comfort

Key aspects of daylit environment

Objectives

Recommended illuminances

Illuminance [lux]Type of space and function Min Mid MaxCirculation, corridors, theatres, concert halls 50 100 200Workshops, retail centres 200 300 400Schools, offices, usual tasks, reading, writing, computer work, … 300 400 500

Delicate work, drawing, technical tasks, ... 500 750 1000Precision workshops, clockwork, color control, visual quality control, … 1000 to 5000

Visual comfort

Visual adaptation

1

/m2

1j/m

2

10 100 1000 0.01

Adaption Level cd

0.1

10

100

Glare

Black Shadow Ob

ect L

umin

ance

cd

1000

10000

100000

Useful Range of Discrimination

Figure by MIT OCW.

Visual comfort

Visual adaptation

Visual field

oo

o o

o

o

o o

o

o

o 0o

330210

240Panorama Ergorama

270300

30

6090

120

150

180 70 50 30 10

Figure by MIT OCW.

Visual comfort

Visual adaptation

Visual field

3

1

Panorama Ergorama

Figure by MIT OCW.

Visual comfort

Visual adaptation

Visual field

1

1

Ergorama

10 10

Panorama

Figure by MIT OCW.

Visual comfort

Visual adaptation

Visual field

Visual performanceperson & taskilluminance on work planeluminance contrastvisual fatigue

Visual comfort

Visual adaptation

Visual field

Visual performanceperson & taskilluminance on work planeluminance contrastvisual fatigueexample: work place

Image courtesy of Prof. B. Paule, Estia SA, Lausanne, Switzerland.

Visual comfort

Visual adaptation

Visual field

Visual performance

Glarephysiological (disability)psychological (discomfort)

Visual comfort

Visual adaptation

Visual field

Visual performance

Glarephysiological (disability)psychological (discomfort)sources: ­ glazed openings & sun patches

Visual comfort

Visual adaptation

Visual field

Visual performance

Glarephysiological (disability)psychological (discomfort)sources: ­ glazed openings & sun patches­ specular reflections

Visual comfort

Visual adaptation

Visual field

Visual performance

Glarephysiological (disability)psychological (discomfort)sources: ­ glazed openings & sun patches­ specular reflections­ inappropriate electric lights

Visual comfort

Tractebel, Brussels

8% 4%

Room 1, Third Floor Room 2, Third FloorN

2% 1% 0.5% 0.5% 1% 2% 4% 8%

Figure by MIT OCW.

Visual comfort

Tractebel, Brussels

Stansted airport, London

W. Richartz Museum, Köln

Visual comfort

Users’ preferencesnatural lightingopen viewvisual effectsharmonious colorsspecific conclusions­ daylight­ sunlight­ windows

Visual comfort

Users’ preferences

Daylight & healthintensity

1 2 3 4 5 6 7 8 9

3

a

c d

e f

b

2.9

Hig

hly

Satis

fied

= 1

Hig

hly

Dis

satis

fied

= 5

Satis

fact

ion

Proportion of Staff Sitting Next to a Window

2.95

3.1

3.05

3.15

3.2

3.25

3.3

3.35

R-squared: .974

Figure by MIT OCW.

Visual comfort

Users’ preferences

Daylight & healthintensityexposure to UV